Bi-directional pump



June 1964 P. w. DOUGLAS 3,

BI-DIRECTIONAL PUMP Filed June 5, 1961 2 Sheets-Sheet l INVENTOR DEYTON \V. DOUGLA ATTORNEY Filed June 5, 1961 2 Sheets-Sheet 2 INVENTOR Dev TON \\l. DOUC Lkb ATTORNEY United States Patent() New York Filed June 5, 1961, Ser. No. 114,933 9 Claims. (Cl. 1032) This invention relates to improvements in a pump for use in effecting the movement of liquid, such as water. More particularly, the invention is directed to a pumpjthat is di-directional in operation and adapted for use in the movement and control of water in a domestic washing machine.

Pumps associated with washing machines, in the past, have been provided primarily as a convenient means for the quick and easy transference of wash or rinse water from a wash tub to another tub or convenient drain. Recently, pumps applied to washing machines have included mechanical features that would" enable selectively diverting the Water back into the tub to provide continuous recirculation as well as effecting tub drainage. In the water line, by which recirculation is obtained, some form of lint filter has been provided to catch or trap foreign matter separated from the clothes during a washing operation. Practically every pump capable of use in this manner has included operative structure such as solenoids, diaphragms, valves, etc. These pumps have been found to be rather highly susceptible to leakage by reason of foreign matter settling or catching in the operative parts. Some few pumps have included bi-directional flipper gates to direct the flow of water or close off the tub drain outlet. -Here again, it was found that foreign matter would collect or settle in or around such'gates and precipitate leakage as well as failing to provide adequate recirculation flow. In other words, pumps such as are used. in currently available washing machines all appear to be susceptible to leakage orbreakdownj.) This of-courseis clue to the fact that clothes would not be in a washingmachine if they did not contain foreign matter and; this mat; ter, when loosened, clogs or impairs the operative parts.

When draining a wash tub it is desirable to empty the .tub in the shortest space of timeinorder that the full washing cycle may not be unduly long. On the other hand, it is desirable, during recirculation of wash water, :to maintain a constant lesser flow. Presently, pumps of .this'nature do not appear to fully meet operational requirements, partly because of by-pass leakage whereby the greater or lesser flow does not function withinthe time period established or set up by a timing mechanism. During a recirculation operation, when flow is; reduced,

it must be maintained at a given constancy to prevent undo pass through a pump, the impeller or otherwater driving member becomes bent, displaced, or broken. At best, such. pumps cannot be expectedto consistently function in accordance with their rated ability or the ability relied upon by a purchaser.

It is an object of the invention to provide a oi-directional pump for liquid that is particularly suited for use in an automatic laundering machine wherein liquid flow, during various washing steps, must be controlled.

It is another object of the invention to provide a bidirectional pump that, due to its specific construction, is substantially impervious to by-pass leakage in either direction of operation.

Another object of the invention is to produce a bi-directional pump that creates a differential flow of liquid in its two directions of operation.

Fatented June, 9,. 1964 Still another object of the invention is to providea bidirectional pump-having impeller blades that not only serve to create a differential flow when rotated in one direction with respect to another but are collapsible to an extent to by-pass. foreign objects without injury.

Other objects and advantages of the invention will be more fully understood from a consideration of the following specification, taken in conjunction with the accompanying drawings; and in which FIG. 1 s a perspective view of one embodiment of the invention when mounted for use in a :washing machine;

FIG. 2, is a side elevational view of the pump as shown and mounted in FIG. 1;

FIG. 3 is a top plan view of the pump;

FIG. 4 is a vertical sectional View taken substantially on the line 4-4 of FIG. 2;

FIG. 5 is ahorizontal sectional view taken substantially on the line 55 of FIG. 2; and

FIG. 6 is an exploded perspective view of the pump, certain partsof the pump casing being broken away to show the impeller in greater detail.

Referring more particularly to the drawings, the reference numeral 10 generally designates a pump embodying the invention. By way of useful orientation, it may be assumed that the pump is mounted on the base 11 of a washing machine and serves to remove or recirculate water in the wash tub. The various ports in the pump will be described in this connection; However, it will be understood that the present more or less specific application'iof use does not preclude its use or adaptation to other circumstances or devices wherein a pump is required to serve in an unusual or particular manner.

More particularly, the pump is'designed to operate as a prime mover of water in' either direction-of rotation and-the water impeller designed to effect different rates of flow. In describing the invention, attention is first directed to the fact that the pump consists of a base and impeller enclosure and a cover or cap. In FIGS. 2 and 4 it will be noted that a generally rectangular body 12 is provided with a central opening 13 in which a bearing sleeve 14 is mounted. The wall defining the upper end of opening 13 is radially outwardlyflared, as at 16, to provide a seat for end thrust and water sealing washers generally designated at 17. These'washers, together with sleeve 14, form a continuous opening for a shaft 18 to which the purnp impeller is secured. The lower end of shaft 18 projects beneath the bottom of base 12 and mounts a pulley 19, held to the shaft by a set screw 21. For convenience in mounting, the sleeve 14 may project slightlybeneath the bottom of; the body 1 2 and provides abutment andlocation forthepulley19, the space between the pulley and the body-enabling mounting and securing the pump on thebase 11, screws 22 being provided for this purpose.

' The upper end of the base 12 is horizontally flanged to provide a generally circular bottom 23 to an impeller compartment 24. This compartment is further defined byanupstanding wall 26 that terminates in a flatrim flange 27. As may be viewed in-FIGS. 5 and 6, the wall 26* is circular frorn'point A to pointiB about a center common tothe shaft 18. From point A this wall is straight, as at 28, andends in a. shoulder 29. .A passageway 31 in the shoulder connects with an outlet pipe 32. From shoulder 29 the compartment wall is semi-circular, as at 33, and terminates in a by-pass fin 34. t This portion of the-wall, while on center with the shaft 18, is in a lesser radius for reasons set out below. From point B the compartment wall 26 flares slightly outwardly, as at 36, and then continues in an arc centered on the shaft 18. Thus, a shielded passageway 37 is created which connects with another and larger outlet pipe 38. i

As clearly shown in FIGS. 4 and 6, the compartment 24 is closed or completed by a cap 39.. Primarily, this cap consists of a flange-like plate 41, the shape and size of which matches the flange or rim 27. Extending upwardly from the, plateis a pipe 42 of relatively large diameter and this pipe serves as a liquid inlet to the compartment 24. Suitable tapped openings 43 are provided in the flange 27 and correspondingly located openings 44 are made in the plate 41. These parts of the pump are secured together by screws 46.

Within the closed compartment 24 is located the impeller which constitutes the essence of the invention in combination with the structural design of the compartmerit in which it rotates. The impeller, generally indicated at 47, may best be described by stating that a hub 48 is mounted on and secured to the upper end of shaft 18. From this hub four uniformly distributed blades 49 extendradially outwardly. The blades, in profile, are of the nature of right angle, triangles, consisting of a vertical wall 51 and an inclined wall 52. The impeller is formed from material that gives it a considerable resiliency, except for the hub which is reinforced by the shaft 18. The base of the impeller is a fiat disk 53 from which the integral blades 49 extend. To render the outerends of the blades more resilient than other portions of the impeller, recesses 54 are created which extend inwardly from the periphery of the disk. The size of these recesses and their depth determine the extent of blade flexibility.

As stated, the present invention is highly suitable for.

use in an automatic washing machine and to this end description of its operation is made as follows: It may be assumed that the large pipe 42 is connected with the base outlet of a collector tank that encloses a clothes and liquid containing wash tub. In the usual cycle of an automatic washer, the tub is filled and a small volume of liquid is allowed to overflow into the collector tank. When agitation takes place, the pump impeller will rotate in a counter-clockwise direction as viewed in FIGS. 5 and 6. The small outlet pipe 32 is connected by a hose with the top of the wash tub. Thus, liquid constantly withdrawn from the collector tank, passes into the washer tub and thence overflows into the collector tank. Of course, the purpose of such circulation is to enable the constant removal of foreign matter from the liquid as the clothes are being cleaned and this is obtained by insertion of a suitable filter in the line between the collector tank outlet and the pump inlet.

Liquid circulation, during the various washing operations, need only be of such volume as to assure passage of the tub contents one or more times through a filter. Due to the fact that the impeller rotates counter-clockwise, the leading blade edges are inclined and therefore do not force the liquid from the pump in suchvolume as would be the case if the blade edges were vertical. Although in the present application of use there is little possibility of any foreign matter entering the pump, it 1s pointed out that the blades, being resilient, would readily deflect should any foreign matter contact them.

In the presently described use of the pump, the wash tube rotates through a spin drying cycle, this following any operation of the agitator. The motor by which the agitator was oscillated, is now reversed and thus the impeller in the pump is caused to rotate in a clockwise direction. This causes the vertical walls 49 of the blades to lead and liquid entering the pump through pipe 42 is now forced out through the large outlet pipe 38 which between outlet 29 and passageway 37. Thus, with counter-clockwise rotation of the impeller, liquid entering the pump will readily enter outlet 29 but will not by-pass it due to contactof the blades with the wall portion 33. This blade contact creates a back syphon as the blades move by the open passageway 37 and, consequently, liquid will have neither the tendency nor the opportunity to flow rom the pump through outlet pipe 38. When the pump impeller rotates in a clockwise direction, liquid, on entering, is swept directly away from the small outlet 29 and, due to the enlarged area from point A to point B and beyond, is caused to follow the wall 26 into the passageway 37 Since the blades successively wipe the semicircular Wall portion 33 directly before passing the opening 29, back syphon is set up which precludes by-pass of liquid into this lesser opening.

From the foregoing, it will be apparent that the present invention has only one moving part; namely, the impeller, and this part, due to its design, creates a high and low flow of liquid when operated as described. Furthermore, the blades of the impellerprevent back flow into either outlet when it is not in use. Thus, valves of any kind are wholly unnecessary and, of course, any structure by which to operate them. It is again pointed out that the impeller will not be damaged, broken or distorted should any of the usual foreign matter find its way into the pump.

Although applicant has described his pump as being suitable for use in an automatic washer wherein a bi-directional motor is used in washing operations, it will be apparent that the invention will find use with other mechanisms as well wherein it is highly advantageous to provide two volume liquid flow and, therefore, any variations in the present structure for adaptation to other devices is considered as being within the spirit and scope of the invention to the extent defined by the annexedclaims.

Having thus set forth my invention, what I claim as new and for which I desire protection by Letters Patent is:

1. A bi-directional liquidiflow pump comprising'a hou ing having a compartment formed by a generally circular side wall and substantially flat top and bottom walls, said top wall having an liquid inlet opening offset from the axis of the generally circular sidewall, said side wall, in an arcuate portion thereof, having a large and a small outlet opening, an impeller in said compartment concentric with the center for said arcuate portion, blades on said impeller extending radially and'being of a length to have operational contact with said'arcuate portion, said blades, in cross section, each being of the nature of a right angle triangle and providing blade surfaces of relatively different angularity whereby said impeller, when rotated in one direction will create a large flow from said pump andwhere rotated in the opposite direction will create a small volume flow from said pump. a

2. bi-directional liquid flow pump comprising a housing having a compartment defined by a top, a bottom and sidewalls, said housing having a liquid inlet opening in the top thereof and liquid outlet openings in one part of the compartment side wall, an impeller in said compartment having uniformly spaced radial blades integral with a disk like base, each of said blades having identically arranged opposed vertical and inclined operating surfaces, the vertical surfaces of said blades, when said impeller rotates in one direction, causing liquid to flow through one of said outlet openingsgthe proximity of said blades to the part of said compartment wall between said outlet openings providinga pressure drop with respect to the other of said outlet openings.

3. A bi-directional liquid flow pump comprising a generally cylindrical pump chamber having a circular sidewall and substantially flat top and bottom walls, said top wall having an inlet openingwhose axis is parallel to the axis of thepump chamber, said sidewall having a pair of circumferentially spaced outlet ports separated by an arcuate portion of sidewall, a liquid impeller in said chamber having blades extending radially thereof to a point adjacent the sidewall, said blades being identical in shape and each having at least two surfaces of unlike angularity with respect to the top wall whereby the direction of rotation establishes the volume of fluid discharge and the outlet port of discharge.

4. A bi-directional liquid flow pump as claimed in claim 3 wherein one of said outlet ports is formed tangentially to the circular sidewall and the other is formed by a bypass fin formed by an arcuate section of the sidewall and carrying liquid from the chamber parallel to the periphery of the circular sidewall.

5. A bi-directional liquid flow pump as claimed in claim 4 wherein one of said blade surfaces lies at an angle of 90 with respect to top wall and delivers fluid to the port formed by the by-pass fin.

6. A bi-directional liquid flow pump as claimed in claim 5 wherein a second blade surface is inclined from the top edge of the said one blade surface away from the top wall providing a surface angularly facing the inlet port and delivering fluid to the outlet port tangential to the side wall and simultaneously forcing fluid back through the inlet port.

7. A bi-directional liquid flow pump as claimed in claim 6 wherein the blade surfaces form in section a right angle triangle.

8. A bi-directional flow pump comprising a generally cylindrical pump chamber having a circular sidewall and substantially flat top and bottom walls, said top wall having an inlet opening whose axis is spaced from and parallel to the aXis of the pump chamber transverse to the plane of the top and bottom walls, said sidewall having a pair of circumferentially spaced outlet ports separated by an arcuate portion of sidewall, a liquid impeller in said chamber rotatable on the axis of said sidewall and having blades extending radially thereof to a point adjacent the sidewall, said blades being identical in shape and each having at least two surfaces of unlike angularity with respect to the top wall whereby the direction of rotation establishes the volume of fluid discharge and the outlet port of discharge.

9. A bi-directional liquid flow pump as claimed in claim 8 wherein the blade is formed of resilient material and the end thereof remote from its axis is recessed behind each surface to permit flexing on striking a solid object.

References Cited in the file of this patent UNITED STATES PATENTS 772,989 Williams Oct. 25, 1904 2,258,284 Findley Oct. 7, 1941 2,460,122 Burks Ian. 25, 1949 2,838,002 Cohen June 10, 1958 2,864,312 Shelton et a1 Dec. 16, 1958 2,884,776 Hughes May 5, 1959 2,899,902 Bandli et al Aug. 18, 1959 2,916,997 Terrie Dec. 15, 1959 2,946,286 Sholtes July 26, 1960 3,040,663 Cashing June 26, 1962 FOREIGN PATENTS 293,772 Switzerland Ian. 4, 1954 

1. A BI-DIRECTIONAL LIQUID FLOW PUMP COMPRISING A HOUSING HAVING A COMPARTMENT FORMED BY A GENERALLY CIRCULAR SIDE WALL AND SUBSTANTIALLY FLAT TOP AND BOTTOM WALLS, SAID TOP WALL HAVING AN LIQUID INLET OPENING OFFSET FROM THE AXIS OF THE GENERALLY CIRCULAR SIDEWALL, SAID SIDE WALL, IN AN ARCUATE PORTION THEREOF, HAVING A LARGE AND A SMALL OUTLET OPENING, AN IMPELLER IN SAID COMPARTMENT CONCENTRIC WITH THE CENTER FOR SAID ARCUATE PORTION, BLADES ON SAID IMPELLER EXTENDING RADIALLY AND BEING OF A LENGTH TO HAVE OPERATIONAL CONTACT WITH SAID ARCUATE PORTION, SAID BLADES, IN CROSS SECTION, EACH BEING OF THE NATURE OF A RIGHT ANGLE TRIANGLE AND PROVIDING BLADE SURFACES OF RELATIVELY DIFFERENT ANGULARITY WHEREBY SAID IMPELLER, WHEN ROTATED IN ONE DIRECTION WILL CREATE A LARGE FLOW FROM SAID PUMP AND WHERE ROTATED IN THE OPPOSITE DIRECTION WILL CREATE A SMALL VOLUME FLOW FROM SAID PUMP. 